Method of treating produce

ABSTRACT

A chlorine dioxide solution is sprayed onto produce that includes at least one contaminant which can be debris, soil, fungus and/or organic chemicals. Sprayers are used to spray the chloride dioxide solution on the produce to wash the contaminant from the produce. The produce may be placed on a conveyor and the conveyor may be used to move the produce under the sprayers while the sprayers are used to spray chlorine dioxide solution onto the produce. The conveyor may include rotating brushes that come in contact with the produce, such that the brushes that brush the produce and mechanically remove debris and residue from the produce. Rinsing sprayers may be provided over the conveying path downstream of the sprayer that sprays the chlorine dioxide solution on the produce. The rinsing sprayers may be used to spray the produce with potable rinse water.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of Ser. No. 08/894,186, filed Aug. 14,1997 now U.S. Pat. No. 5,863,584 and entitled Method For TreatingProduce And Process Water.

TECHNICAL FIELD

This invention relates to a method for treating produce to removedebris, organic chemicals, and hard water deposits from the produce andinhibit the formation of mold on the produce, and more particularly, toa method of cleaning, sanitizing, and descaling produce by the use of aneffective amount of a chlorine dioxide. solution.

BACKGROUND INFORMATION

After harvest, fresh produce is washed before being sorted and packed.Once clean produce has been sorted and packed, fungus adhering to thesurface of the produce may cause mold to develop before the produce hasreached market. The presence of fungus on even one piece of produce in acrate can cause decay of substantially all of the produce in the crate.For these reasons, it is desirable to reduce the occurrence of decay inpacked produce so that the overall value of the harvested produce isincreased.

If produce is treated by process water, the used process water containscontaminants and debris. Conventionally, process water for treatingproduce has been used for a short time before being dumped due to thebuildup of contaminants in the process water.

DISCLOSURE OF THE INVENTION

The present invention provides a method for treating process water andan object submerged in process water when the process water and theobject include at least one contaminant from the group of debris, soil,fungus, and organic chemicals.

The method comprises passing the produce under a flow of a chlorinedioxide solution to wash debris from the produce. The chlorine dioxidesolution may be generated by the reaction of a solution comprisingsodium chlorite with a solution comprising phosphoric acid, sodium2-ethylhexyl sulfate, and either dodecylbenzenesulfonic acid or sodiumdodecylbenzene sulfonate. Alternatively, the chlorine dioxide solutionmay be generated by the reaction of a solution comprising sodiumchlorite and sodium chloride with a solution comprising phosphoric acid,sodium 2-ethylhexyl sulfate, and either dodecylbenzenesulfonic acid orsodium dodecylbenzene sulfonate.

A chlorine dioxide solution may be delivered to sprayers and thesprayers and may be used to spray the chlorine dioxide solution on theproduce to wash contaminants from the produce. The produce may be placedonto a conveyor and the conveyor may be used to move the produce underthe sprayers. During movement, the sprayers may be used to spraychlorine dioxide solution onto the produce. Rotating brushes may beprovided and the produce may be placed in contact with the rotatingbrushes, so that the brushes will brush the produce and mechanicallyremove debris and residue from the produce. A plurality of rinsingsprayers may be positioned over the conveying path of the conveyordownstream of the sprayers that spray the chlorine dioxide solution. Therinsing sprayers may be used to spray the produce with potable rinsewater.

These and other advantages and features will become apparent from thedetailed description of the best mode for carrying out the inventionthat follows.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like element designations refer to like partsthroughout the several views, and:

FIG. 1 is schematic view of produce cleaning assembly line used in themethod of the present invention;

FIG. 2 is a fragmentary schematic view of the chlorine dioxide generatorand controller shown in FIG. 1; and

FIG. 3 is a fragmentary schematic view of another chlorine dioxidegenerator and controller shown in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1 and 2, a produce washing assembly line 10 is shown.The assembly line 10 includes a dump tank 12 and a bin conveyor 14 whichhas an entrance side 16, a tank portion 18, and an exit side 20. Aprocess water control loop 22 extends off of the dump tank 12. Theprocess water control loop 22 has an inlet 24 from the dump tank 12 intothe loop 22 and an outlet 26 from the loop 22 into the dump tank 12. Afilter 28 is positioned on the inlet 24 of the control loop 22. Processwater from the dump tank 12 is pumped through the loop 22 so that thecomposition of the process water can be monitored and maintained.

A process water controller 30 and a chlorine dioxide reactor 32 areattached. to the control loop 22. The process water controller 30includes an Oxidation Reduction Potential (ORP) probe 34 which sensesthe ORP residual in the process water passing through the control loop22. The controller 30 also includes a flow indicator 36 which indicatesto the controller 30 that process water is flowing through the loop 22.When the flow indicator 36 indicates that process water is flowingthrough the loop 22, the controller 30 enables the ORP probe 34 tomeasure the ORP residual in the process water. If the ORP probe 34indicates that the ORP residual in the process water is too low, thecontroller 30 activates the chlorine dioxide reactor 32 to generatechlorine dioxide solution.

A pH probe 38 monitors the pH of the process water. Storage tanks 40, 42of pH adjusting agents are attached to pumps 44, 46 which are controlledby controller 30. Storage tank 40 stores a pH reducing agent. Storagetank 42 stores a pH boosting agent. The controller 30 is operable forfeeding pH adjusting agents into the process water.

The controller 30 controls a first pump 48 and a second pump 50 whichare attached to a first storage tank 52 and a second storage tank 54,respectively. The pumps 48, 50 are operable for pumping solutions fromthe storage tanks 52, 54 to the reactor 32. The controller 30 activatespumping of proportional amounts of solutions from each of the tanks 52,54.

An apple conveyor 56 extends into the dump tank 12. The apple conveyor56 is operable for moving apples out of the dump tank 12 and through aseries of stations before the apples are sorted, sized and packed. Thefirst station along the apple conveyor 56 includes a plurality ofrotating brushes 58 and a spray bar 60. The spray bar 60 is operable foremitting a flow of a second chlorine dioxide solution 62 onto apples.The chlorine dioxide solution 62 is monitored and produced by a chlorinedioxide generation system 64, shown in more detail in FIG. 3.

The chlorine dioxide generation system 64 includes an inlet 66 which isoperable for feeding potable water through conduit 68 past flow meter70. The flow meter 70 is operable for transmitting flow rate informationto controller 72. Controller 72 is operable for signalling a first pump74 to pump a solution from a first storage tank 76 and a second pump 78to pump a solution from a second storage tank 80. The first and secondpumps 74, 78 are operable for pumping solutions to reactor 82 throughfeed lines 84 and 86. The chlorine dioxide solution from the reactor 82are fed through line 88 and into conduit 68 which feeds into the spraybar 60.

Further down the apple conveyor 56 from the spray bar 60 is a rinsingsprayer 90. The rinsing sprayer 90 is operable for rinsing apples withpotable water. The next station along the apple conveyor 56 is a dryingstation 92. The drying station 92 includes a fan 94 for blowing ambienttemperature air over apples on the conveyor 56. Following the dryingstation 92 is a waxing station 96 which includes a plurality of rotatingbrushes 98 and an overhead spraying mechanisms 100 which are operablefor spraying wax on the surface of apples. After the waxing station 96is a final drying station 102 which includes a fan 104 which is operablefor blowing heated air on apples on the conveyor 56.

In a preferred form of the invention, the produce washing assembly line10 is operated in the following manner. The dump tank 12 is filled withapproximately 3,000 gallons of process water 106. The process water 106is monitored by pumping the process water 106 through the control loop22. As process water 106 enters the inlet 24 of the control loop 22, theprocess water 106 passes through the filter 28. The filter 28 separatesparticulate matter, such as leaves, twigs, and other orchard debris,from the process water 106. In a preferred form of the invention, thecontrol loop 22 includes a differential switch (not shown) installed onthe filter 28 for measuring the accumulation of particulate matter onthe filter 28. When a predetermined level of particulate matter hasaccumulated on the filter 28, the differential switch activates anautomatic backwash (not shown) which washes the particulate matter outof the system through conduit 108.

The process water 106 is admixed with between about 0.1 and about 10 ppmchlorine dioxide solution from the reactor 32. In a more preferred formof the invent the the process water 106 is admixed with between about0.5 and about 1.0 ppm chlorine dioxide solution. In an even morepreferred form of the invention, the process water 106 is admixed withabout 1.0 ppm chlorine dioxide solution.

Preferably, the process water 106 admixed with the chlorine dioxidesolution has a pH of less than 11, and in a more preferred form of theinvention, a pH of between about 2 and about 10.5, and more commonly,between about 3 and about 10. If the apples being cleaned in theassembly line 10 are heavily scaled, i.e. covered in hard waterdeposits, the pH of the process water 106 admixed with the chlorinedioxide solution is maintained well below 7, and preferably at about 3.If the apples are not scaled, but instead are covered mainly in debris,such as orchard soil, the pH of the process water 106 admixed with thechlorine dioxide solution is maintained at between about 7 and about 10.Accordingly, the preferred pH of the process water 106 admixed with thechlorine dioxide solution depends on the type of debris present on theapples 114 and in the process water 106.

The chlorine dioxide solution is generated by reacting one part of aFirst Solution fed by the first pump 48 from tank 52 with between oneand five parts of a Second Solution fed by the second pump 50 from tank54. In a preferred form of the invention, one part of the First Solutionis reacted with two parts of the Second Solution. The First Solutioncomprises an active ingredient of sodium chlorite. In a more preferredform of the invention, the First Solution comprises 9.4% of 80%technical sodium chlorite and the balance water. In another form of theinvention, the First Solution comprises 9.4% of 80% technical sodiumchlorite, 15% sodium chloride and the balance water.

The Second Solution comprises phosphoric acid as an active ingredient.It is preferable to include an anionic surfactant and coupling agent,such as sodium 2-ethylhexyl sulfate in the Second Solution. In a morepreferred form of the invention, the Second Solution comprises 1% sodium2-ethylhexyl sulfate, 7.5% phosphoric acid and the balance water.

The First Solution and the Second Solution are fed into the reactor 32by pumps 48, 50. In the reactor 32, the First Solution and SecondSolution are allowed a contact time of at least about 15 minutes. Whenthe controller 30 determines that more chlorine dioxide solution isneeded in the process water 106 due to the reading of the ORP probe 34,the controller 30 activates the pumps 48, 50 to feed more of the Firstand Second Solution to the reactor 32. As the First and Second Solutionsenter the reactor 32, the chlorine dioxide solution in the reactor 32 isdisplaced from the reactor 32 into conduit 110 which empties into theloop 22 and into the dump tank 12.

Substantial foaming of the chlorine dioxide solution is undesirablesince foam could be detrimental to the pumps 48, 50 on the control loop22. Accordingly, it is preferred that the First Solution and the SecondSolution include surfactants which produce little to no foam.

The controller 30 monitors and controls the composition of the processwater 106 in the following manner. The desired ORP level is set on thecontroller 30. The ORP level is indicative of a particular chlorinedioxide residual in the process water 106. The pH of the process water106 is monitored by the pH probe 38.

As process water 106 flows through loop 22, the pH probe 38 monitors thepH of the process water 106. If the pH in the process water 106 is toohigh, the second pump 50 is activated to pump a higher proportion of theSecond Solution from storage tank 54 to the reactor 32. Generally, thesecond pump 50 is manually calibrated to pump a higher proportion of theSecond Solution for pH control, although it is foreseeable that thiscalibration of the second pump 50 could be automated. The amount of theSecond Solution can be increased until the 5 parts of the SecondSolution are being fed for each 1 part of the First Solution. Generally,it is undesirable to feed the Second Solution at a rate higher than 5parts for each 1 part of First Solution since proper reactions may nottake place in the reactor 32.

If a lower pH is desired, an effective amount of a pH reducing agent maybe added to the process water 106. The controller 30 activates pump 44to pump pH reducing agent from storage tank 40 to feed through conduit110 and into the process water 106. In a preferred form of theinvention, the pH reducing agent comprises phosphoric acid as an activeagent. Sodium 2-ethylhexyl sulfate may be present in the pH reducingagent to provide an increase in surface activity. In a more preferredform of the invention, the pH reducing agent comprises 26.25% phosphoricacid, 1.4% sodium 2-ethylhexyl sulfate and the balance water.

If the pH of the process water 106 is too low, the controller 30activates pump 46 to pump pH boosting agent from storage tank 42 intofeed to the process water 106. Preferably, the pH boosting agentcomprises sodium hydroxide. A chelant, such as sodium gluconate, may bepart of the boosting agent to aid in cleaning mineral type debris. In amore preferred form of the invention, the pH boosting agent comprises42.5% sodium hydroxide, 17.5% sodium gluconate, and the balance water.

Bins 112 of freshly-harvested apples 114 are placed on the entrance side16 of the bin conveyor 14. The apples 114 may have contaminants such asdebris, orchard soil, fungus, organic chemicals such as agriculturalchemicals, and hard water scale on their surfaces. As the bins 112 moveinto the tank portion 18 of the conveyor 14, the bins 112 becomesubmerged in process water 106 in the dump tank 12. The apples 114 floatout of the bins 112 into the process water 106 in the dump tank 12.While the apples 114 are in the dump tank 12, the apples 114 arecleaned, descaled, and sanitized by contact with the process water 106which has admixed with it the chlorine dioxide solution. As the apples114 float toward the surface of the dump tank 12, a water current (notshown) pushes the apples 114 toward the apple conveyor 56. Preferably,the apples 114 remain in the dump tank 12 for at least 30 seconds beforebeing pushed onto the conveyor 56. An estimated 75-85% of the cleaning,descaling, and sanitizing of the apples 114 is accomplished by theprocess water 106 comprising the chlorine dioxide solution in the dumptank 12.

Along with the apples 114 being cleaned, descaled and sanitized by theprocess water 106 in the dump tank 12, the bins 112 are cleaned andsanitized. As the apples 114 float to the surface of the dump tank 12,the bins 112 continue along the bin conveyor 14 and out the exit side 20of the conveyor 14 for re-use.

An additional benefit of the present invention is the treatment of theprocess water 106. Just as the chlorine dioxide solution treats theapples 114 and the bins 112, organic chemicals and contaminants in theprocess water 106 are treated by the chlorine dioxide solution. Withoutthe use of the chlorine dioxide solution in the process water in thedump tank, the process water became brown, had an unpleasant odor, andwas full of sludge after apples had been washed in the system for a fewdays. With the addition of the chlorine dioxide solution to the processwater 106, the process water 106 remains clear and odorless, even afterweeks of treating apples in the system.

As the apples 114 proceed down the apple conveyor 56, the apples 114roll on top of the rotating brushes 58 and pass underneath the spray bar60. The spray bar 60 emits a second chlorine dioxide solution 62 ontothe apples 114. The second chlorine dioxide solution 62 is generated bythe generation system 64 illustrated in FIG. 3. The generation system 64is operated by feeding potable water through the inlet 66 of conduit 68.The flow of potable water is monitored by flow meter 70. The readingsfrom flow meter 70 are transmitted to controller 72. The controller 72signals pumps 74, 78 to pump solutions from storage tanks 76, 80. Thesolutions are fed to the reactor 82 and then into the potable water inconduit 68 to create the chlorine dioxide solution 62. Storage tank 76stores the First Solution, as described above. Storage tank 80 stores aThird Solution.

The controller 72 activates pumps 74, 78 to pump First Solution andThird Solution from tanks 76, 80, respectively, through feed lines 84,86 and into the reactor 82. As the solutions enter the reactor 82,previously generated product is expelled from the reactor 82 into line88 and then into conduit 68 where it mixes with the water to form thesecond chlorine dioxide solution 62. Preferably the solutions areallowed a contact time of at least about 15 minutes in the reactor 82.

The Third Solution comprises an anionic surfactant, such asdodecylbenzenesulfonic acid or sodium dodecylbenzene sulfonate, and ananionic surfactant coupling agent, such as sodium 2-ethylhexyl sulfate.In a preferred form of the invention, the Third Solution can be in theform of 1.6% sodium 2-ethylhexyl sulfate, 4% dodecylbenzenesulfonicacid, 7.5% phosphoric acid, and the balance water. In another form ofthe invention, the Third Solution comprises 3% sodium 2-ethylhexylsulfate, 7.5% dodecylbenzenesulfonic acid, 15% phosphoric acid, and thebalance water. The sodium 2-ethylhexyl sulfate provides stabilizingproperties in the second chlorine dioxide solution 62 so that thesolution 62 will feed through the spray bar 60 without substantialclogging.

The controller 72 controls flow rates of the First Solution and ThirdSolution to the reactor 82 such that the second chlorine dioxidesolution 62 has a chlorine dioxide residual of between about 0.1 ppm andabout 10 ppm. It is preferred that the second chlorine dioxide residualin the solution 62 is between about 1 and about 5 ppm. Although, thesolution 62 is generally very effective at about 1.0 ppm.

In a preferred form of the invention, the chlorine dioxide solution 62is generated by reacting one part of the First Solution, as describedabove, with between one and five parts of the Third Solution. In an evenmore preferred form of the invention, one part of the First Solution isreacted with 5 parts of the Third Solution.

The pH of the second chlorine dioxide solution 62 is monitored.Preferably, the pH of the solution 62 is between about 3 and about 7. Ina more preferred form of the invention, the pH of the solution 62 ismaintained at about 3. If the pH of the solution 62 is too high, more ofthe Third Solution is fed to the reactor 82. To adjust the pH, the feedrate of the Third Solution can be increased to 5 parts for each 1 partof the First Solution. Generally, it is undesirable to feed the ThirdSolution at rates higher than 5 parts for each one part of the FirstSolution, since undesired reactions may take place in the reactor 82.

The second chlorine dioxide solution 62 emitted by the spray bar 60completes, cleaning, descaling, and sanitizing of the apples 114. Thedodecylbenzenesulfonic acid or sodium dodecylbenzene sulfonate in theThird Solution which is fed to the chlorine dioxide reactor 82 producesa slight bubbling of the solution 62 from the spray bar 60 which ishelpful for indicating to an observer that a chlorine dioxide is presentin solution 62. As the apples 114 pass over the rotating brushes 58, theapples 114 are tumbled by the brushes 58 so that chlorine dioxidesolution 62 is emitted from the spray bar 60 onto all surfaces of theapples 114. Further, the frictional action of the brushes 58 on theapples 114 provides a mechanical agitation of the apples 114 whichgently wipes debris and residue from the surface of the apples 114.After passing over the apples 114, the second chlorine dioxide solution62 may pass to a drain (not shown) or be added to the process water 106in the dump tank 12.

As the apples 114 continue on the apple conveyor 56, the apples 114 passunder the rinsing sprayer 90 which emits potable water onto the apples114 to remove residual amounts of chlorine dioxide solution 62 from thesurface of the apples 114. After the rinsing sprayer 90, the apples 114enter drying station 92 where a fan 94 blows ambient temperature airover the surface of the apples 114. The apples 114 are driedsufficiently in the drying station 92 so that wax will adhere to thesurfaces of the apples 114 during the next phase of processing.

After the apples 114 have been dried, the apples 114 continue on theapple conveyor 56 to the waxing station 96. As the apples 114 passthrough the waxing station 96, the apples 114 are tumbled on rotatingbrushes 98 as an overhead spraying mechanisms 100 sprays wax onto theapples 114. The rotating brushes 98 spread the wax across the surface ofthe apples 114. After the waxing station 96, the apples 114 are movedinto the final drying station 102 where heated air is blown across thesurface of the apples 114 by fan 104 to completely dry the apples 114.After the apples 114 exit the final drying station 102, the apples 114proceed to sorting and sizing stations (not shown) for final packing.

This invention provides a simple and effective method for cleaning,sanitizing, and descaling produce after harvest. The method of thepresent invention would be useful on many types of produce, such aspears, peaches, plums, apricots, oranges, grapefruit, lemons, limes,avocados, cantaloupe, honeydew, watermelon, zucchini, squash, carrots,potatoes, and cucumbers. In addition, the present invention provides asimple and effective method for cleaning and sanitizing of contaminatedwater or other contaminated objects submerged in water, such as applebins.

In addition, the present invention provides a safe and effective methodfor the use of a chlorine dioxide solution by allowing for on sitegeneration. According to the present invention, small amounts ofchlorine dioxide solutions, including solutions with up to 50% activechlorine dioxide, can be generated on site as needed. Accordingly, thepresent invention provides environmental and safety benefits byeliminating the need for the shipment, storage, and handling ofhazardous chlorine dioxide solutions.

The nature and substance of the instant invention as well as its objectsand advantages will be more clearly understood by referring to thefollowing specific examples.

EXAMPLE 1

Apples were rolled in moist orchard soil until they were covered withsoil. Then, the apples were allowed to dry. Once dry, the apples wereallowed to soak in a 5 ppm solution of chlorine dioxide produced from areaction of one part of First Solution with one part of Second Solution.No direct brush action was applied. After one minute, an apple wasremoved from the chlorine dioxide solution. Based upon visual inspectionof the apple, approximately 95% of the soil had been removed from thesurface of the apple. After 30 minutes, another apple was removed fromthe chlorine dioxide solution. Based upon visual inspection of theapple, approximately 98% of the soil had been removed from the surfaceof the apple.

EXAMPLE 2

Three identical containers were obtained. Container #1 was filled with achlorine dioxide solution having a concentration of chlorine dioxide at5 ppm. The solution was obtained from a reaction of one part of FirstSolution with one part of Second Solution. Container #2 was filled witha chlorine dioxide solution having a chlorine dioxide concentration of11 ppm. The solution was obtained from a reaction of one part of FirstSolution with one part of Second Solution. Container #3 was filled withdeionized water. Mold was introduced into each of the containers. Afirst sample was taken from each of the three containers after fiveminutes. A second sample was taken from each of the three containersafter 50 minutes. All samples were placed onto prepared mold growthmedia and allowed to incubate for three days. At the end of three days,the mold plates were observed. For the samples taken from the 5 ppm and11 ppm chlorine dioxide solutions, the samples showed negative for moldgrowth. For the samples taken from the solution which contained nochlorine dioxide, the sample showed positive for mold growth.

EXAMPLE 3

Two identical one liter volumetric flasks were obtained. Flask #1 wasfilled with deionized water and Flask #2 was filled with an 8 ppmchlorine dioxide solution. The chlorine dioxide solution was obtainedfrom a reaction of one part of First Solution with one part of SecondSolution. Both flasks were spiked with precisely the same amount ofo-phenylphenol. When tested, 7 ppm residual of o-phenylphenol waspresent in Flask #1. Flask #2 showed a mild visual reaction uponaddition of the o-phenylphenol. When tested, 1 ppm residual ofo-phenylphenol was present in Flask #2.

EXAMPLE 4

Two identical one liter volumetric flasks were obtained. Flask #1 wasfilled with deionized water and Flask #2 was filled with an 8 ppmchlorine dioxide solution. The chlorine dioxide solution was obtainedfrom a reaction of one part of First Solution with one part of SecondSolution. Both flasks were spiked with precisely the same amount of1-hydroxyethylidene-1, 1-diphosphonic acid (HEDPA). When tested, 6 ppmresidual of HEDPA was present in Flask #1. Flask #2 showed a mild visualreaction upon addition of the HEDPA. When tested, Flask #2 indicatedthat no HEDPA residual was present.

EXAMPLE 5

Two identical one liter volumetric flasks were obtained. Flask #1 wasfilled with deionized water and Flask #2 was filled with an 8 ppmchlorine dioxide solution. The chlorine dioxide solution was obtainedfrom a reaction of one part of First Solution with one part of SecondSolution. Both flasks were spiked with precisely the same amount ofchlorophenol red (an organic dye). Flask #1 tested for positive forapproximately 8 ppm chlorophenol red. Residual was determined visuallyby the presence of a reddish color. Flask #2 tested for virtually nochlorophenol red as determined by Flask #2 being absolutely colorlessupon visual inspection.

While specific embodiments of the present invention have been shown anddescribed in detail to illustrate the utilization of the inventiveprinciples, it is to be understood that such showing and descriptionhave been offered only be way of example, and not by way of limitation.Protection by Letters Patent of this invention in all its aspects areset forth in the appended claims and is sought to the broadest extentthat the prior art allows.

What is claimed is:
 1. A method of treating produce that includes atleast one contaminate from the group consisting of debris, soil, fungusand/or organic chemicals, said method comprising:generating a chlorinedioxide solution by the reaction of a solution comprising sodiumchlorite with a solution comprising phosphoric acid, sodiumII-ethylhexyl sulfate, and either dodecylbenzenesulfonic acid or sodiumdodecylbenzene sulfonate; providing sprayers; delivering said chlorinedioxide solution to the sprayers; and using said sprayers to spray thechlorine dioxide solution on said produce to wash said contaminate fromthe produce.
 2. The method of claim 1, further comprising placing theproduce onto a conveyor and using the conveyor to move the produce underthe sprayers, and during movement using the sprayers to spray chlorinedioxide solution onto the produce.
 3. The method of claim 2, furthercomprising a plurality of rinsing sprayers over the conveying path ofthe conveyor downstream of the sprayer that spray the chlorine dioxidesolution on the produce, whereby the rinsing sprayers may be used tospray the produce with potable rinse water.
 4. The method of claim 2,further comprising providing the conveyor with rotating brushes, androtating said brushes while they are in contact with the produce, sothat the brushes will brush the produce and mechanically remove debrisand residue from the produce.
 5. The method of claim 1, furthercomprising providing rotating brushes, and, placing the produce incontact with the rotating brushes, so that the brushes will brush theproduce and mechanically remove debris and residue from the produce.